1. Field of the Invention
The invention relates to a spacer clip allowing sheet products such as panes of glass, and especially windscreens, rear screens or side windows, of motor vehicles to be handled and transported.
2. Description of the Related Art
Devices allowing sheets of glass, especially windscreens, to be handled and transported are known. A device of this kind is described, for example, in French patent application 2,506,728. This application describes a metal pallet or box forming a floor and provided with vertical curtain walls intended to protect the sheets of glass which are standing edgewise thereon.
To space the panes of glass apart, they are placed in the gaps between the teeth of racks arranged on the floor of the pallet. The gaps are as wide as the thickness of the sheets to be transported so that the sheets can be held fast.
Spacer clips intended to maintain the spacing between two sheets of glass over their entire area are placed on the upper edges of the glass sheets. These spacer clips may also provide supports for binding straps or bars, avoiding the risk of damaging the edges of the glass panes.
These devices are very widely used in the glazing industry for handling panes of glass. Improvements have already been made to these types of devices. For example, the materials of which the "boxes" are made have been modified to make them lighter, and the shapes of the "boxes" have been modified to reduce the amount of space they occupy when they are not in use. An important advantage of these pallets or boxes is that they can be reused.
As regards the insert clips, it is advantageous for their upper part to have an essentially horizontal surface, especially to provide a region suited to the passage of binding straps or bars. When a clip is placed on a sheet of glass, the position of its upper surface depends on the inclination of the panes of glass; these panes are not stored or transported precisely upright but always slightly inclined to make the "stacked" products more stable, this inclination being given by the gaps between teeth of the rack arranged on the floor of the pallet or box.
To compensate for this inclination, a common approach is to make such clips in such a way that the upper surface is at an angle to the direction of the jaws, so that this upper surface is more or less horizontal when the clip is placed on the pane of glass.
Added to this inclination is another inclination due to the shape of the pane of glass, especially when this pane is curved in the vertical direction, as arranged on the pallet. As the spacer clip straddles the edge of a sheet of glass, the direction given to the jaws is a tangent to the edge of the sheet and therefore depends on the curvature of the latter in the vertical direction. As panes of glass for motor vehicles, whether they be windscreens, rear screens or even side windows, increasingly have two curvatures, i.e., curvatures in two directions perpendicular to each other, a curvature in the vertical direction when the panes of glass are stacked on a box or pallet is very often encountered. This second inclination which is due to the curvature of the sheets of glass can also be compensated for by the angle between the upper surface and the direction of the lower jaws of the clip.
In contrast, although the inclination of the sheets of glass on a pallet can be made constant irrespective of the pallet or the sheets of glass, the inclination due to the curvature of the sheets of glass will vary from one series of sheets to another.
At present, it is necessary to have one type of spacer clip for each type of sheet of glass, so that the upper surfaces of the clips are always more or less horizontal. This solution is feasible but has many drawbacks: first, it leads to high costs because it is necessary to have several manufacturing molds, usually employed for short runs. In addition, it is necessary for each workshop that prepares the pallets to have a stock of various types of spacer clips. Furthermore, each type of clip needs to be indexed to let the operator know which clips correspond to a particular type of pane of glass. These requirements inevitably lead to higher costs.